Re^3: Merging Two Strings

Those are spec issues, not defects in my solution. There's no spec saying what happens if there's no overlap, so how is it wrong to return a string with a space in it? It's better than starting a game of nethack or deleting all the files on the user's disk.

The maximal overlap rule conflicts with the last-overlap rule. Doing maximal overlap is easier than what I posted (you remove the first capture group and substitute nothing in). And changing the + to a * ensures that the space gets removed, even if the overlap is empty. Does this conform to your understanding of the specs?

$catted =~ s/(.*) (?=\1)//;
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Caution: Contents may have been coded under pressure.

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Re^4: Merging Two Strings by GrandFather (Saint) on Oct 27, 2005 at 19:43 UTC
That merges ATGATG and ATGATG as ATGATG - not wnat OP gave as an explicit example. The problem is that a regex finds the first match, which may not be the best match. In this case the first match is the whole string, the best match is the last repeated substring (ATG). Perl is Huffman encoded by design.	[reply]
Re^5: Merging Two Strings by Roy Johnson (Monsignor) on Oct 27, 2005 at 19:47 UTC
Yes, there are conflicting specs. The OP now states that if two patterns are equal, it simply returns one of them (ie, the whole thing matches). If you want the other behavior, look a couple of posts up and you'll see where I solved it (and saouq complained about it, leading to the solution you're now criticizing). Caution: Contents may have been coded under pressure.	[reply]
Re^4: Merging Two Strings by sauoq (Abbot) on Oct 27, 2005 at 21:49 UTC
Does this conform to your understanding of the specs? Yes.(More precisely, with my assumption about which of the OP's examples is wrong.) I think that's almost equivalent^† to my much more verbose, probably slower, certainly uglier c-style function. Very nice. ++ † It would be completely equivalent except that yours won't work on arbitrary binary data since you require a unique character not otherwise present in the strings to build your concatenation. That obviously wouldn't pose a problem for the OP, however. -sauoq "My two cents aren't worth a dime.";	[reply]